Note: Descriptions are shown in the official language in which they were submitted.
PCT/US93/11910
WO 94/13239
DISPOSABLE ABSORBENT ARTICLE HAVING AN
IMPROVED MECHANICAL FASTENING SYSTEM
FIELD OF THE INVENTION
The present invention relates to disposable absorbent
articles having mechanical fastening systems, more particularly
to an absorbent pad, such as a sanitary napkin or incontinent
pad, which is positioned and worn in the crotch portion of the
wearer's panties or other undergarment.
BACKGROUND OF THE INVENTION
All manner and variety of absorbent articles configured for
the absorption of body fluids such as menses, urine, and feces
are, of course, well known. Absorbent articles, particularly
sanitary napkins, pantiliners, incontinent pads, and the like are
disclosed in the literature and are available in the marketplace.
Generally, absorbent articles will comprise a central
absorbent means or central pad which is provided with a means for
securing the central pad to the crotch of a wearer's
undergarment. Currently available absorbent articles,
particularly sanitary napkins and pantiliners, are positioned in
an undergarment, such as woman's panties, and secured thereto by
pressure-sensitive adhesive. While the use of adhesive is
common, there are a number of drawbacks such as comfort, adhesive
contamination, residual build-up on panties, the inconvenience of
and noise produced by the protective sheets, and the like.
2 ~~ ~ ~ ~~
Absorbent articles having wings or flaps are also disclosed in the literature
and are available in the marketplace. Generally, the flaps of such absorbent
articles extend laterally from a central absorbent means and are intended to
be
folded around the edges of the wearer's panties in the crotch region. Thus,
the
s flaps are disposed between the edges of the wearer's panties in the crotch
region
and the wearer's thighs. Commonly, the flaps are provided with an adhesive
attachment means, or flap adhesive, for affixing the flaps to the underside of
the
wearer's panties.
The flaps serve at least two purposes. First, the flaps prevent exudates
1 o which otherwise would soil the edges of the wearer's panties from doing
such.
Second, the flaps help stabilize the napkin from shifting out of place,
especially
when the flaps are affixed to the underside of the panties.
Sanitary napkins having flaps of various types are disclosed in U.S. Patent
4,687,478, entitled "Shaped Sanitary Napkin With Flaps", which issued to Van
15 Tilburg on August 18, 1987, U.S. Patent 4,608,047, entitled "Sanitary
Napkin
Attachment Means", which issued to Mattingly on August 26, 1986, U.S. Patent
4,589,876, entitled "Sanitary Napkin", which issued to Van Tilburg on May 20,
1986, U.S. Patent 4,285,343, entitled "Sanitary Napkin", which issued to
McNair
on August 25, 1981, U.S. Patent 3,397,697, entitled "Disposable Sanitary
Shield
2o for Undergarments", which issued to Rickard on August 20, 1968, and U.S.
Patent
2,787,271, entitled "Sanitary Napkin", which issued to Clark on April 2, 1957.
A common problem with disposable absorbent articles such as sanitary
napkins, is that the central absorbent means will frequently shift from its
original
position during wear due to stresses caused by body motion and/or the pressure
of
2 s the thighs and buttocks. Shifting can also occur when the wearer's pants
(or other
outer garment) are being pulled up. This is particularly true if the wearer's
pants
are tight-fitting. If the fastener which holds the central absorbent means to
the
crotch of the wearer's panties is an adhesive fastener, then this
.,
WO 94/13239 215I ~ 8 5 PCT/US93/11910
shi fti ng of the absorbent arti cl a can resul t i n the central pad
adhesive sticking to itself causing "bunching" of the central
absorbent means within the panty. Shifting of the central
absorbent means may also occur if the adhesive of the adhesive
fastener is aged or if there is insufficient adhesive.
In addition to the shifting and bunching of the central
absorbent means, a common problem with disposable absorbent
articles having flaps or wings, is that the fasteners which hold
the flaps to the wearer's panties will frequently "pop" loose
from the panty when the panty is being pulled up or when the
wearer's pants (or other outer garment) are being pulled up.
Again, this is particularly true if the wearer's panty, pants, or
other outer garment are tight-fitting. If the fastener which
hol d the fl aps to the wearer's panti es i s an adhesi ve fastener,
then this popping loose of the fastener can result in the flap
adhesive sticking to itself, to the body of the wearer, or to an
extraneous surface.
Mechanical fasteners are an alternative to pressure
sensitive adhesives. Absorbent articles having mechanical
fastener means are disclosed in the art. Although the use of
mechanical fasteners avoids some of the drawbacks of the adhesive
fasteners such as adhesive contamination, residual build-up on
panties, and the inconvenience of and noise produced by the
protective sheets, disposable absorbent articles using mechanical
fasteners are still subject to the shifting of the central
absorbent means and the popping loose of the flap adhesives upon
application of the wearer's pants. Disposable absorbent articles
using mechanical fasteners generally do not suffer from
"bunching" as do disposable absorbent articles using adhesive
fasteners. However, disposable absorbent articles using
mechanical fasteners will still suffer from misalignment in the
crotch of the wearer's panties as a result of shifting of the
central absorbent means and will still suffer from the flaps
popping loose.
Therefore, there is a need for an absorbent article
comprising a mechanical fastener which can hold the flaps
securely to the crotch of a wearer's undergarment without popping
~ 5 ~~~5
loose upon application of the wearer's pants or other outer garment. There is
also
a need for an absorbent article comprising a mechanical fastener which can
hold
the absorbent article securely in place without unwanted shifting of the
central
absorbent means upon application of the wearer's pants or other outer garment.
There is also a need for an absorbent article comprising a mechanical fastener
which can hold the absorbent article securely in place without unwanted
shifting
of the absorbent article during use.
It is therefore an aspect of an object of the present invention to provide a
disposable absorbent article comprising a mechanical fastener which can
maintain
1 o the absorbent article securely in the panty of the user without popping
loose upon
pulling up the weaxer's panty, pants, or other outer garment.
It is also an aspect of an object of the present invention to provide a
disposable absorbent article comprising a mechanical fastener which can
maintain
the absorbent article securely in the panty of the user without unwanted
shifting of
i 5 the absorbent article.
It is also an aspect of an object of the present invention to provide an
absorbent article comprising a mechanical fastener having engaging elements
which are arranged such that any shifting of the absorbent article will tend
to
improve the positioning of the absorbent article in the undergarment.
2 o It is an aspect of an additional obj ect of the present invention to
provide a
disposable absorbent article comprising a mechanical fastener which tends to
maintain the absorbent article in intimate contact with the body of the
wearer.
It is an aspect of an additional obj ect of the present invention to provide a
disposable absorbent article comprising a mechanical fastener which does not
2 s need a dedicated receiving surface but which can be secured to the panty
material
or the materials of the disposable absorbent article itself.
SUMMARY OF THE INVENTION
The present invention relates to an absorbent article for wearing in the
3 o crotch region of an undergarment which. is comprised of a fibrous
material.
The absorbent article has a body-facing side and a garment side. The
absorbent article comprises a main body portion comprising longitudinal edges,
transverse edges, a transverse center, a first transverse end, a second
transverse
end, an absorbent assembly capable of absorbing fluids, a pad securement
3 s member, and a principal transverse centerline which divides said main body
.;
portion into a first half and a second half;
said pad securement member comprising an oriented hook fastening
material joined to the garment side of said first half and an oriented hook
fastening
material joined to the garment side of said second half, said oriented hook
fastening material comprising a plurality of engaging elements joined to a
substrate, and said oriented hook fastening material of said first half and
said
oriented hook fastening material of said second half being generally oriented
in a
direction having a vector component perpendicular to said principle transverse
centerline.
1 o In an alternate embodiment of the present invention, the disposable
absorbent article will have side flaps joined to the main body portion and an
oriented hook fastening material joined to the side flaps.
In another alternate embodiment of the present invention, the disposable
absorbent article will have a combination of a pressure sensitive adhesive and
an
oriented mechanical fastening system.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and
distinctly claiming the invention, it is believed the invention will be better
2 o understood from the following description taken in conjunction with the
associated drawings in which like elements are described by the same reference
numeral or letter and related elements are designated by adding one or more
prime
symbols:
Figure 1 is a top plan view of a sanitary napkin embodiment of the present
2 5 invention with the garment side facing the viewer;
Figure 1 a is a sectional view of the sanitary napkin of Figure 1 taken along
section line a-a;
y
WO 94/13239 ~ PCT/US93/11910
6
Figure 2 is a top plan view of an alternate sanitary napkin
embodiment of the present invention with the garment side facing
the viewer;
Figure 3 is a top plan view of an alternate sanitary napkin
embodiment of the present invention with the garment side facing
the viewer;
Figure 3a is a top plan view of an alternate sanitary napkin
embodiment of the present invention with the garment side facing
the viewer;
Figure 3b is a top plan view of an alternate sanitary napkin
embodiment of the present invention with the garment side facing
the viewer;
Figure 4a is a side elevational view of an engaging element
of a particularly preferred oriented hook fastening material;
Figure 4b is a side elevational view of an engaging, element
of another oriented hook fastening material;
Figure 4c is a side elevational view of an oriented hook
fastening material;
Figure 4d is a side elevational view of another oriented
hook fastening material;
. Figure 5 is a top plan view of an alternate sanitary napkin
embodiment of the present invention with the garment side facing
the viewer and having flaps joined to the main body portion;
Figure 6 is a perspective view of the crotch portion of a
women's panties;
Figure 6a is the same perspective view of the women's
panties shown in Figure 6 with the sanitary napkin embodiment of
the present invention being placed therein for use;
Figure 7 is a top plan view of an alternate sanitary napkin
embodiment of the present invention with the garment side facing
the viewer;
Figure 7a is a top plan view of an alternate sanitary napkin
embodiment of the present invention with the garment side facing
the viewer; and
Figure 7b is a top plan view of an alternate sanitary napkin
embodiment of the present invention with the garment side facing
the viewer.
"",. ~. 6 a
Figure 8A is an enlarged top plan view of a portion
of the garment side of the sanitary napkin~of Figure 1
in the first half;
Figure 8B is an enlarged top p lan view of a portion
of the garment side of the sanitary napkin of Figure 1
in the second half;
Figure 9A is an enlarged parti al sectional view
of
the sanitary napkin of Figure lA in the first half;
Figure 9B is an enlarged parti al sectional view
of
the sanitary napkin of Figure lA in the second half;
Figure l0A is an enlarged top plan view of a
portion of the garment side of the sanitary napkin of
Figure 2 in the first quarter;
Figure lOB is an enlarged top plan view of a
portion of the garment side of the sanitary napkin of
Figure 2 in the second quarter;
Figure lOC is an enlarged top plan view of a
portion of the garment side of the sanitary napkin of
Figure 2 in the third quarter;
Figure lOD is an enlarged top plan view of a
portion of the garment side of the sanitary napkin of
Figure 2 in the fourth quarter;
Figure 11A is an enlarged top plan view of a
portion of the garment side of the sanitary napkin of
Figure 3 in the first quarter;
Figure i1B is an enlarged top plan view of a
portion of the garment side of the sanitary napkin of
Figure 3 in the second quarter;
Figure 11C is an enlarged top plan view of a
portion of the garment side of the sanitary napkin of
Figure 3 in the third quarter;
Figure 11D is a top plan view of a portion of the
garment side of the sanitary napkin
of Figure 3 in the
fourth quarter;
'A
'~"... 6 b r~ ~ ~ ~ r
Figure 12A is an enlarged top plan view of a
portion of the oriented hook fastening material on the
garment side of the sanitary napkin of Figure 3A in the
first quarter;
Figure 12B is an enlarged top plan view of a
portion of the oriented hook fastening material on the
garment side of the sanitary napkin of Figure 3A in the
second quarter;
Figure 12C is an enlarged top plan view of a
portion of the oriented hook fastening material on the
garment side of the sanitary napkin of Figure 3A in the
third quarter;
Figure 12D is an enlarged top plan view of a
portion of the oriented hook fastening material on the
garment side of the sanitary napkin of Figure 3A in the
fourth quarter;
Figure 12E is an enlarged top plan view of a
portion of the oriented hook fastening material on the
garment side of the sanitary napkin of Figure 3A in the
transverse center;
Figure 12F is an enlarged top plan view of a
portion of the other oriented hook fastening material
on
the garment side
of the sanitary
napkin of Figure
3A in
the transverse center;
Figure 13A is an enlarged top plan view of a
portion of the oriented hook fastening material on the
garment side of the sanitary napkin of Figure 3B in the
first quarter;
Figure 13B is an enlarged top plan view of a
portion of the oriented hook fastening material on the
garment side of the sanitary napkin of Figure 3B in the
second quarter;
A
6c
Figure 13C is an enlarged top plan view of a
portion of the oriented hook fastening material on the
garment side of the sanitary napkin of Figure 3B in the
third quarter;
Figure 13D is an enlarged top plan view of a
portion of the oriented hook fastening material on the
garment side of the sanitary napkin of Figure 3B in the
fourth quarter;
10. Figure 13E is an enlarged top plan view of a
portion of the oriented hook fastening material on the
garment side of the sanitary napkin of Figure 3B in the
transverse cent er;
Figure 13F is an enlarged top plan view of a
portion of the other oriented hook fastening material
on
the garment sid e of the sanitary napkin of Figure 3B
in
the transverse center;
Figure 13G is an enlarged top plan view of a
portion of the oriented hook fastening material on the
garment side of the sanitary napkin of Figure 3B at the
longitudinal ce nter in the first half;
Figure 13H is an enlarged top plan view of a
portion of the oriented hook fastening material on the
garment side of the sanitary napkin of Figure 3B at the
longitudinal ce nter in the second half;
Figure 14A is an enlarged top plan view of a
portion of the oriented hook fastening material on the
flap of the san itary napkin of Figure 5;
Figure 14B is an enlarged top plan view of a
portion of the oriented hook fastening material on the
other flap of t he sanitary napkin of Figure 5;
Figure 14C is an enlarged top plan view of a
portion of the garment side of the sanitary napkin of
Figure 5 in the first half;
A
6d
Figure 14D is a top plan view of a portion of the
garment side of the sanitary napkin of Figure in the
5
second half;
Figure 15A is an enlarged top plan view a
of
portion of the oriented hook fastening materialof the
sanitary napkin of Figure 7 in the first half;
Figure 15B is an enlarged top plan view a
of
portion of the oriented hook fastening materialof the
sanitary napkin of Figure 7 in the second half;
Figure 16A is an enlarged top plan view a
of
portion of the oriented hook fastening materialof the
sanitary napkin of Figure 7A in the first half;
Figure 16B is an enlarged top plan view a
of
portion of the oriented hook fastening materialof the
sanitary napkin of Figure 7A in the second half;
Figure 17A is an enlarged top plan view a
of
portion of the oriented hook fastening materialof the
sanitary napkin of Figure 7B in the first half;
Figure 17B is an enlarged top plan view a
of
portion of the oriented hook fastening materialof the
sanitary napkin of Figure 7B in the second half;
Figure 17C is an enlarged top plan view a
of
portion of the of the
oriented hook
fastening material
sanitary napkin of Figure 7B at the longitudinalcenter,
and
Figure 17D is an enlarged plan view of a portion of
the other oriented hook fastening material of the
sanitary napkin of Figure 7B at the longitudinal center.
A
WO 94/13239 7 ~~ ~~~ PCT/LTS93/11910
DETAILED DESCRIPTION OF THE INVENTION
1. Introduction
A. The Absorbent Article In General
The present invention relates to absorbent articles, such as
sanitary napkins. More particularly, the present invention
relates to absorbent articles comprising an oriented hook
fastening material.
The term "absorbent article", as used herein, refers to
articles which absorb and contain body exudates. More
specifically, the term refers to articles which are placed
against or in proximity to the body of the wearer to absorb and
contain the various exudates discharged from the body. The term
"absorbent article" is intended to include sanitary napkins,
pantiliners, and incontinent pads (and other articles worn in the
crotch region of a garment). The term "disposable" refers to
articles which are intended to be discarded after a single use
and preferably recycled, composted, or otherwise disposed of in
an environmentally compatible manner. (That is, they are not
intended to be laundered or otherwise restored or reused as an
absorbent article.)
The term "sanitary napkin", as used herein, refers to an
article which is typically worn by females adjacent to the
pudendal region that is intended to absorb and contain the
various exudates which are discharged from the body (e. g., blood,
menses, and urine). The present invention, however, is not
limited to the particular types or configurations of absorbent
articles shown in the drawings.
As used herein, the term "oriented hook fastening material"
will refer to a mechanical fastening system having engaging
elements that are oriented such that the mechanical fastening
. system will have little or no shear strength when the mechanical
fastening system is moved in a first direction relative to a
receiving surface and will have a relatively high shear strength
when the mechanical fastening system is moved relative to the
WO 94/13239 ~ PCT/US93/11910
8
receiving surface in the direction opposite the first direction
or i~n a direction having a vector component oriented in a
direction opposite the first direction. Having little or no
shear strength in a first direction, does not mean that the
engaging element or elements of the hook fastening material must
break or fail when the hook fastening material is moved in the
first direction. It simply means that the engaging elements of
the fastening system are arranged, oriented, or configured such
that they will not engage the fibers of the receiving surface
when the hook fastening material is moved in the first direction.
Therefore, the hook fastening material should be able to move in
the first direction with relative ease. Having a relatively high
shear strength in a direction opposite the first direction, means
that the arrangement, orientation, or configuration of the
engaging elements of the mechanical fastening system, is such
that the engaging elements will engage the fibers of the
receiving surface when the hook fastening material is moved in a
direction opposite the first direction or is moved in a direction
having a vector component oriented in a direction opposite the
first direction. Therefore, the mechanical engagement of the
engaging elements with the receiving surface will restrict or
substantially prevent movement of the hook fastening material in
the direction opposite the first direction or in a direction
having a vector component oriented in a direction opposite the
first direction.
It is not necessary that all of the engaging elements of the
hook fastening material be oriented in the same direction. It is
only necessary that a sufficient number of engaging elements be
oriented to provide the hook fastening material with little or no
sheer strength in a first direction and a relatively high sheer
strength in a direction opposite the first direction. It will be
clear to one skilled in the art that the direction of orientation, .
of a hook fastening material will be generally determined by the
direction of orientation of a majority of the engaging elements
of that hook fastening material.
As used herein, the term "engaging elements" will refer to the elements of
a hook fastening material which are intended to mechanically engage the
fibrous
elements of a receiving surface such as woven or nonwoven fabrics or loop
fastening materials which are well known in the art.
Suitable receiving surfaces for use with the present invention include
knitted fabrics, nonwoven materials, reticulated foams, and stitchbonded loop
materials, such as VelcroTM brand loop materials sold by VelcroTM USA of
Manchester, New Hampshire. Particularly preferred receiving surfaces are the
woven material of a woman's undergarment and the nonwoven elements of the
1 o sanitary napkin such as the topsheet material or flap material.
The terms "oriented hook fastening material" and "hook fastening
material" will be used interchangeably herein. It should be understood that
the use
of the term "hook" should be non-limiting in the sense that the engaging
elements
may comprise any shapes known in the art so long as they are adapted to engage
a
15 loop fastening material or other fibrous material.
A preferred embodiment of an absorbent article of the present invention,
sanitary napkin 20, is shown in Figure 1. As shown in Figure 1, the sanitary
napkin 20 basically comprises an absorbent means represented by central
absorbent pad (or "main body portion") 22 and a pad securement member 67
2o comprising an oriented hook fastening material 54, joined thereto. The main
body
portion 22 is divided into a first half 80 and a second half 82 by a principle
transverse centerline T. An oriented hook fastening material 54 is joined to
the
first half 80 and second half 82 of the main body portion 22 such that the
hook
fastening material of the first half 80 is oriented in a direction
substantially
2 5 opposite to the direction of orientation of the hook fastening material of
the
second half 82. However, both the hook fastening material of the first half 80
and
the hook fastening material of the second half 82 are oriented toward the
transverse centerline.
In addition to the principal transverse centerline T, the sanitary napkin 20
3 o has a principal longitudinal centerline L
~;
WO 94/13239 ~ PCT/US93/11910
2151~~~
which divides the main body portion into four quarters, 86, 87,
88, and 89. The term "longitudinal", as used herein, refers to a
line, axis or direction in the plane of the sanitary napkin 20
that is generally aligned with (e.g., approximately parallel to)
a vertical plane which bisects a standing wearer into left and
right body halves when the sanitary napkin 20 is worn. The term .
"transverse" used herein refers to a line, axis or direction
which lies within the plane of the sanitary napkin 20 that is
generally perpendicular to the longitudinal direction.
If the sanitary napkin is provided with flaps or wings, then
the sanitary napkin will also have a flap transverse centerline
T1 which is parallel to the principle transverse centerline T and
bisects the flaps or wings of the sanitary napkin 20 as shown in
Figure 5. In some embodiments, the flaps 24 may be positioned
slightly forward of the principal transverse centerline T of the
sanitary napkin. In such a case, the flap transverse centerline
T1 does not coincide with the principal transverse centerline T
of the sanitary napkin. The flaps 24, however, are preferably
evenly spaced from the principal longitudinal centerline L of the
sanitary napkin.
The sanitary napkin 20 is comprised of a topsheet 40, a
backsheet 42, and an absorbent core 44. At 1 east a part of the
topsheet 40, backsheet 42, and absorbent core 44 comprise the
main body portion 22. The hook fastening material 54 is
comprised of an array of engaging elements 55 joined to a
substrate 124. As used herein, the term "joined" encompasses
configurations whereby an element is directly secured to the
other element by affixing the element directly to the other
element; configurations whereby the element is indirectly secured
to the other element by affixing the element to intermediate
members) which in turn are affixed to the other element; and
configurations whereby one element is integral with the other .
element, i.e., one element is essentially part of the other
element. The substrate 124 of the hook fastening material 54 may
be comprised of portions of the garment side 20b of the sanitary
napkin 20, e.g., the engaging elements are secured directly to
the backsheet 42 of the sanitary napkin 20, as shown in Figures 1
j PCT/US93/11910
WO 94/13239
11
and la. (In alternative embodiments, such as that shown in
Figure 3, the substrate 124 of the hook fastening material 54 may
be comprised of a discrete piece (or pieces) of material which is
joined to the garment side 20b of the sanitary napkin 20, e.g.,
the engaging elements are indirectly secured to the backsheet 42
of the sanitary napkin 20.)
2. The Individual Components of the Absorbent Article
The individual components of the sanitary napkin 20 will
first be looked at in greater detail.
A. The To~sheet
The topsheet 40 is liquid permeable and when the sanitary
napkin 20 is in use, the topsheet 40 is in close proximity to the
skin of the user. The topsheet 40 is compliant, soft feeling,
and non-irritating to the user's skin. It can be made from any
of the materials conventional for this type of use. Nonlimiting
examples of suitable materials that can be used as topsheet 40
are woven and nonwoven polyester,~polypropylene, nylon, and rayon
and formed thermoplastic films, with formed films being
preferred.
Suitable formed films are described in U.S. Patent
3,929,135, entitled "Absorptive Structure Having Tapered
' Capillaries", which issued to Thompson on December 30, 1975, U.S.
Patent 4,324,426, entitled "Disposable Absorbent Article Having A
Stain-Resistant Topsheet", which issued to Mullane and Smith on
April 13, 1982, U.S. Patent 4,342,314, entitled "Resilient
Plastic Web Exhibiting Fiber-Like Properties", which issued to
Radel and Thompson on August 3, 1982, and U.S. Patent 4,463,045,
entitled "Macroscopically Expanded Three-Dimensional Plastic Web
Exhibiting Non-Glossy Visible Surface and Cloth-Like Tactile
Impression", which issued to Ahr, Louis, Mullane, and Ouellette
on July 31, 1984. Formed films are preferred for topsheet 40
because they are pervious to liquids and yet non-absorbent.
12
Thus, the surface of the formed film which is in contact with the body remains
dry
and is more comfortable to the wearer.
The sanitary napkin 20 may also be comprised of components that are
extensible (i.e., capable of stretching, particularly in the longitudinal
direction)
when the sanitary napkin is worn. The sanitary napkin 20 may be capable of
elongating between about 15% and about 40% of its unstretched length. This
extensibility provides better in-use fit, comfort, and decreased staining. In
other
embodiments, only limited portions of the components of the sanitary napkin 20
are capable of stretching. Such an embodiment (without the oriented hook
1 o fastening material of the present invention) is described in greater
detail in
Canadian Patent Application No. 2,079,537-9 filed September 30, 1992.
A particularly preferred topsheet 40 for use in such an embodiment is one
which is made in accordance with U.S. Patent 4,463,045 and ring rolled to
provide
it with a degree of longitudinal extensibility. Suitable processes for ring
rolling or
15 "pre-corrugating" are described in U.S. Patent 4,107,364 issued to Sisson
on
August 15, 1978, U.S. Patent 4,834,741 issued to Sabee on May 30, 1989 and in
U.S. Patent 5,167,897 granted December 1, 1992; U.S. Patent 5,156,793 granted
October 20, 1992; and U.S. Patent 5,143,679 granted September 1, 1992. The
fold lines in the corrugations of the topsheet should run in the transverse
direction
2 o so the topsheet is longitudinally extensible.
Such a topsheet is described in greater detail in the following patent
applications: Canadian Patent Application No. 2,073,815-4 filed July 14, 1992;
Canadian Patent Application No. 2,073,849-9 filed July 14, 1992; and Canadian
Patent Application No. 2,113,416 filed July 6, 1992.
2 s In addition, in preferred embodiments of the present invention, at least a
portion of the outer surface 40a of the topsheet 40 is treated with a
surfactant. It is
preferred that the surfactant be substantially evenly and completely
distributed
across at least the portion of the outer surface 40a of topsheet 40 that
overlays the
main body portion 22. This can be accomplished by any of the common
3 o techniques well known to those skilled in the art. For example, the
surfactant can
be applied to topsheet 40 by spraying, by padding, by the use of transfer
rolls, or
by incorporating the surfactant into the formulation of the topsheet.
Treating the outer surface 40a of the topsheet 40 with a surfactant renders
the surface of the topsheet 40 more hydrophilic. This results in liquid
penetrating
3 5 the topsheet 40 faster than it would if the surface were not treated. This
~ . ..,~
w.___
13
diminishes the likelihood that menstrual fluids will flow off topsheet 40
rather
than being absorbed by the absorbent core 44. Preferably, any portions of the
topsheet 40 that overlay the flaps 24 are not treated with the surfactant.
This will
minimize any tendencies fluids may have to spread laterally across the flaps
and to
come in contact with the wearer's thighs and other parts of the wearer's body
or
garments.
.~- t(-~y...
F., 1. i ,,.~,,V
PCT/US93/11910
WO 94/13239 ~ ' 14
In preferred embodiments, the inner surface 40b of topsheet
40 is secured in contacting relation with the absorbent core 44.
This contacting relationship results in liquid penetrating
topsheet 40 faster than if the topsheet 40 were not in contact
with absorbent core 44. The topsheet 40 can be maintained in
contact with absorbent core 44 by applying adhesive to the inner
surface 40b of the topsheet 40. Suitable adhesives useful for
this purpose are described in U.S. Patent 4,917,697. The
adhesives can be applied by the same methods as the surfactant is
applied to the outer surface 40a of the topsheet 40.
B. The Absorbent Core
The absorbent core 44 is positioned between the topsheet 40
and the backsheet 42. The absorbent core 44 provides the means
for absorbing menstrual fluid. The absorbent core 44 need not
have an absorbent capacity much greater than the total amount of
menstrual fluid anticipated to be absorbed. The absorbent core
44 is generally compressible, conformable, and non-irritating to
the user's skin. It can comprise any material used in _the art
for such purpose. Examples include comminuted wood pulp which is
generally referred to as airfelt, creped cellulose wadding,
absorbent foams, absorbent sponges, synthetic staple fibers,
polymeric fibers, hydrogel-forming polymer gelling agents, peat
moss, or any equivalent material or combinations of materials.
Polymeric gelling agents are those materials which, upon
contact with fluids (i.e., liquids) such as water or body fluids,
imbibe such fluids and thereby form hydrogels. In this manner,
fluids discharged into the absorbent core 44 can be acquired and
held by the polymeric gelling agent, thereby providing the
articles herein with enhanced absorbent capacity and/or improved
fluid retention performance.
The polymeric gelling agent which is employed in the
absorbent core 44 will generally comprise particles of a
substantially water-insoluble, slightly cross-linked, partially
neutralized, hydrogel-forming polymer material. The term
"particles", as used herein, can refer to particles in any form,
15
such as in the form of pellets, flakes, or fibers. The characteristics of the
absorbent core 44 (including, but not limited to the preferred types of
polymer
materials used therein, and types of methods which can be used for preparing
these polymer particles) are described in greater detail in U.S. Patent
5,009,653
issued to Osborn.
In one preferred embodiment, the absorbent core 44 is a laminate
comprised of a layer of superabsorbent polymer material, such as in the form
of
particles, disposed between two air-laid tissues, first and second tissue
layers (or
"upper" and "lower" tissue layers). The. first and second tissue layers
provide
1 o containment of the superabsorbent polymer material, improve lateral
wicking of
the absorbed exudates throughout the absorbent core 44 and provide a degree of
absorbency.
A suitable laminate is the superabsorbent laminate WATER-LOCK L-535
available from the Grain Processing Corporation of Muscatine, Iowa (WATER-
15 LOCK registered TM by Grain Processing Corporation). Such superabsorbent
laminates are disclosed in U.S. Patent 4,467,012, entitled "Composition For
Absorbent Film And Method Of Preparation", which issued to Pedersen et al. on
August 21, 1984, and U.S. Patent 4,260,443, entitled "Laminated Absorbent
Process", which issued to Lindsay et al. on April 7, 1981.
2 o The absorbent core 44 may be a laminate, as described above, which is
slitted or partially slitted for longitudinal extensibility. This slitted or
partially
slitted core is described in greater detail in the Capillary Channel Fiber
patent
applications.
2 s C. The Backsheet
The backsheet 42 is impervious to liquids and, thus, prevents menstrual
fluid from soiling the clothing of the user. Any material used in the art for
such
purpose can be utilized herein. Suitable materials include embossed or
.,;
3 o nonembossed
WO 94/13239 ~ PCT/LJS93/11910
16
polyethylene films and laminated tissue. A suitable polyethylene
film is manufactured by Monsanto Chemical Corporation and
marketed in the trade as Film No. 8020.
In one alternative embodiment of the sanitary napkin 20
(typically in which the topsheet 40 overlays only the main body
portion 22 and does not extend out to form the top surface of the
flaps), the backsheet 42 may be comprised of two layers. In such
a case, the backsheet 42 may comprise a first layer of lofted
material disposed on the core-facing side 42a of the backsheet.
The purpose of the first layer is to provide a comfortable,
non-irritating surface against the body of the wearer. The
lofted layer may be comprised of any suitable material, such as a
nonwoven material. Preferably, the lofted layer comprises a
hydrophobic nonwoven material. The second layer may be disposed
on the garment side 42b of the backsheet 42, and may comprise a
fluid impervious film. A low density polyethylene material about
0.01 to about 0.05 millimeters in thickness, preferably about
0.02 millimeters in thickness, has been found to work well as
this second layer. A polyethylene film, such as is sold by the
Ethyl Corporation, Yisqueen Division, under model XP-39385 has
been found particularly well suited for this second layer. The
backsheet 42 may also be made of a soft, cloth-like material
which is hydrophobic relative to the topsheet 40. A polyester or
polyolefinic fiber backsheet 42 has been found to work well. A
particularly preferred soft, cloth-like backsheet 42 material is
a laminate of a polyester nonwoven material and a film such as
descri bed i n U. S. Patent 4, 476,180 i ssued to Wnuk on October 9,
1984.
A particularly preferred extensible backsheet 42 is an
extended adhesive film Formula #198-338 manufactured by the
Findley Adhesives Company of Wauwatosa, Wisconsin which is
described in greater detail in the Capillary Channel Fiber patent
applications.
3. Assembly of Components into a Sanitary Napkin
A. Assembly of Comaonents
WO 94/13239 PCTIUS93111910
17
As shown in Figures 1 and la, the topsheet 40 is secured to
backsheet 42 al ong a fi rst seam, such as seam 36. The seam 36
can be formed by any means commonly used in the art for this
purpose such as by gluing, crimping, or heat-sealing. The seam
36.is illustrated in Figure 1 as extending completely around the
periphery of the main body portion 22. This is a preferred
embodiment for ease of construction. (Other means of uniting the
various elements can be used.)
The main body portion 22 is the portion of the sanitary
napkin 20 that contains an absorbent means, such as absorbent
core 44. The main body portion 22 has a liquid pervious body
contacting surface (represented in Figure la by topsheet 40) and
an opposed liquid impervious surface (represented in Figure la by
backsheet 42). It is to be understood that the embodiment
illustrated is only one possible embodiment, albeit a preferred
one. Other possible embodiments include one in which an
absorbent core 44 is essentially completely wrapped with topsheet
before it is placed on a backsheet. In another alternative
embodiment, the absorbent core 44 may be positioned on the
backsheet 42 and then the absorbent core 44 and the backsheet 42
may be essentially completely wrapped with the topsheet 40. The
main body portion 22 can also comprise an absorbent core which
possesses sufficient integrity to stand alone and is liquid
pervious on one surface while the other surface has been treated
to render it liquid impervious.
The main body portion 22 may be relatively thick or
relatively narrow and thin. A thin main body portion may be
desired because it is typically comfortable to the user.
B. Construction and Function of the Oriented Hook
Fastenin4 Material
1. Hook Fastenin4 Material
The hook fastening material 54 comprises an array of
engaging elements 55 joined to a substrate 124 and provides a
secure attachment of the sanitary napkin 20 to the crotch of the
WO 94/13239 PCTIUS93111910
211485 1$
user's undergarment. The hook fastening material 54 is joined in
a predetermined pattern to the garment side 20b of the sanitary
napkin 20, usually the backsheet 42 . The hook fastening
material 54 will be oriented in a direction having a vector
component perpendicular to the principle transverse centerline T.
Therefore, as shown in Figures 1 and 2, the hook fastening
material of the first half 80 and the hook fastening material of
the second half 82 will be oriented in substantially opposite
directions (as shown in Figure 1) or will be oriented in
directions having vector components oriented in substantially
opposite directions (as shown in Figure 2). This configuration
of the hook fastening materials provides a secure attachment of
the sanitary napkin 20 to the undergarment by having the engaging
elements of the first half 80 and the engaging elements of the
second half 82 pulling fibers of the undergarment in opposite
directions. This configuration of the hook fastening material 54
also results in the main body portion 22 being maintained in
close proximity to the body. Such proximity of the main body
portion 22 places it precisely where it should be: very near the
body at the vaginal opening. The main body portion 22 can then
absorb the vast majority of the menstrual fluid (menses) before
it has an opportunity to flow along the sides of the main body
portion 22. The function of the sanitary napkin will be
described in greater detail with relation to the wearer's
undergarments.
It will be apparent to one skilled in the art that the
direction of orientation of a hook fastening material will be
generally determined by the direction of orientation of a
majority of the engaging elements of that hook fastening
material. The direction of orientation of an individual engaging
element generally corresponds with the direction of orientation
of the maximum lateral projection 138 of the engaging element.
Referring to Figure 4a, the maximum lateral projection 138
is that projection from the origin 136 to the outer periphery of
the shank 128 or engaging means 130. The origin 136 of the shank
128 is found with the prong 122 in the profile view (as shown in
Figure 4a). The "origin" of the shank 128 is the point which may
WO 94113239 ~ PCT/US93/11910
'19
be thought of as the center of the base 126, and is typically
within the footprint of the base 126. The origin 136 is found by
viewing the prong 122, from the side view. The "side view" is
any direction radially towards the shank 128 and base 126 which
is also parallel to the plane of the substrate 124. The lateral
distance between the remote edges 150, 152 of the base 126
footprint for the particular side view under consideration is
found, and this distance is bisected, yielding the midpoint of
the base 126 for such view. When bisecting the footprint of the
base 126 for the particular side view under consideration, minor
discontinuities (such as fillets or asperities incident to the
attachment to substrate 124) are ignored. This point is the
origin 136 of the shank 128.
The side view of the prong 122 which maximizes the lateral
projection 138 is the profile view of such prong 122. The side
elevational view shown in Figure 4a is one of the profile views
of the prong 122. It will be further apparent to one skilled in
the art that there is another profile view, generally 180n
opposite from the profile view shown (so that the maximum lateral
projection 138 is oriented towards the left of the viewer).
Either of the two profile views is generally equally well suited
to determine the maximum lateral projection 138 of the prong 122
and, therefore, for determining the direction of orientation of
the prong 122.
The engaging elements 55 of an oriented hook fastening
material 54 will tend to engage fibers of a receiving surface
when the hook fastening material is moved relative to the
receiving surface in the same direction as the direction of
orientation of the hook fastening material, or in a direction
having a vector component oriented in the same direction as the
direction of orientation of the hook fastening material. The
engaging elements engaging the fibers of the receiving surface
will restrict or prevent further movement of the hook fastening
material 54 in that direction. When the oriented hook fastening
material 54 is moved relative to a receiving surface in the
direction opposite the direction of the orientation of the hook
fastening material 54, or in a direction having a vector
WO 94/13239 ~ , PCT/US93111910
component oriented in the direction opposite the direction of the
orientation of the hook fastening material 54, the engaging
elements 55 will tend to not engage fibers of the receiving
surface and movement of the hook fastening material 54 in that
direction will tend to be unrestricted. (The direction of
orientation for the engaging elements 55 shown in Figures 4a, 4b,
4c, and 4d, is represented by the arrow designated S.)
Referring to Figure 1, the hook fastening material 54 of the
first half 80 is oriented in a direction substantially
perpendicular to the principal transverse centerline T. The hook
fastening material 54 of the second half 82 is also oriented in a
direction substantially perpendicular to the principal transverse
centerline T. However, the hook fastening material 54 of the
second half 82 is oriented in a direction substantially opposite
the direction of orientation of the hook fastening material 54 of
the first half 80. (The orientation of the engaging elements is
shown more clearly in the circular insets of Figures 1 - 3.)
Although the engaging elements of the hook fastening
material are not limited to "hooks", hooks are the preferred
engaging element. An especially preferred hook fastening
material comprises engaging elements such as the prong 122 shown
in Figure 4a. It should be understood that although a hook
fastening material comprising prongs 122 is particularly
preferred as the hook fastening material of the present
invention, there are other suitable hook fastening materials
comprising various suitable engaging elements. Examples of other
suitable hook fastening material are shown in Figures 4b, 4c, and
4d. However, for clarity and simplicity, the present invention
will be described as comprising a hook fastening material 54 such
as that depicted in Figure 4a.
Referri ng to Fi gure 4a, the prong 122 wi 11 compri se a base
126, shank 128 and engaging means 130. The base 126 of the prong
122 contacts and adheres to the substrate 124, and supports the
proximal end of the shank 128. The shank 128 projects outwardly
from the substrate 124 and base 126. The shank 128 terminates at
a distal end which is joined to an engaging means 130. The
engaging means 130 radially projects laterally (i.e., in a
WO 94113239 PCT/US93/11910
21
direction having a vector component generally parallel to the
plane of the substrate 124 at the principal prong 122 under
consideration) from the shank 128 in one or more directions and
may resemble a hook-shaped tine. The projection of an engaging
means 130 from the shank 128 periphery in a lateral direction
allows the engaging means 130 to be secured to a complementary
receiving surface (such as the fibrous material of the
undergarment 11 shown in Figure 6). The engaging means 130 is
joined to, and preferably contiguous with, the distal end of the
prong 122.
Associ ated wi th each prong 122 i s a 1 ongi tudi nal axi s 132 .
As used herein, the term "longitudinal axis" refers to an
imaginary line generally centered at the footprint of the base
126 and laterally and longitudinally projecting through the
distal end of the shank 128 to the tip 134 of the engaging means
130. The prong base 126, shank 128 and engaging means 30 are
generally concentric with the longitudinal axis 132 if the prong
122 cross section is of a regular shape. If the cross section of
the prong 122 is irregularly shaped, the longitudinal axis 132 is
disposed at the centroid of any cross section. The "origin" of
the longitudinal axis is the same as the origin of the shank, and
is found as described herei~nbefore.
The engaging means 130 forms an included angle 8 relative to
the plane of the substrate 124. As used herein, the term
"included angle A" refers to the angular deviation between the
extension of the perpendicular to the plane of the substrate 124
which passes through the origin 136 of base 126 and the
projection of the longitudinal axis 132 through the tip 134 of
the engaging means 130, as seen when the prong 122 is viewed in
profile. The phrase "projection of the longitudinal axis" refers
to the imaginary continuation of the longitudinal axis 132 in a
straight line through the tip 134 of the engaging means 130 if
such axis were continued at the angle present at the tip 134 of
the engaging means 130.
It i s to be recogni zed that as the i ncl uded angl a 8 of the
engaging means 130 increases, i.e. departs further from the
perpendi cul ar to the pl ane of the substrate 124, i t wi 11 become
22
increasingly difficult for the engaging means 130 to intercept the strands or
fibers
of the receiving surface. For any of the embodiments described herein, the
engaging means 130 preferably has an included angle 8 of between about
90° to
about 160°. More preferably, the included angle 8 is between about
100° to about
s 150°, and most preferably is between about 110° to about
140°. However, a prong
122 having an included angle 0 greater than about 160° or less than
90° may also
be used.
The array of prongs 122 may be produced by any suitable method.
Preferably, the prongs 122 are produced by methods which yield free formed
1 o prongs. Preferably, the prongs 122 are formed of thermoplastic material,
such as
hot melt adhesive thermoplastics. Polyester and polyamide hot melt adhesives
are
particularly well suited for forming the free formed prongs 122 of the
preferred
hook fastening material 54. The free formed prongs 122 are preferably
manufactured using a modified gravure printing process or a screen printing
15 process, by printing the thermoplastic material in its molten state onto a
substrate
in discrete units, severing the material in a manner that allows stretching of
a
portion of the thermoplastic material prior to severance, and allowing the
stretched
molten material to "freeze" resulting in prongs. This preferred hook fastening
material and methods and apparatus for making such a hook fastening material
are
2 o more fully detailed in U.S. Patent 5,230,851 granted July 27, 1993; U.S.
Patent
5,058,247, issued October 22, 1991 to Dennis A. Thomas and Ted L. Blaney; and
U.S. Patent 5,116,563, issued May 26, 1992 to Dennis A. Thomas and David J.K.
Goulait.
Methods of orienting the prongs relative to the machine direction, are
2 5 disclosed in Canadian Patent 2,109,620 granted January 28, 1993; and U. S.
Patent
5,180,534 granted January 19, 1993.
Because the hook fastening material 54 is intended to mechanically engage
the fibrous material of the user's undergarment so as to provide a secure
attachment of the sanitary napkin 20 to the crotch of the user's undergarment,
the
3 o prongs 122 are preferably small and the array of prongs is preferably
dense, so that
23
the hook fastening material 54 will not irritate the skin of the wearer and
will be
able to engage the fibers of the wearer's undergarment. A method for making
such a dense array of small prongs is disclosed in Canadian Patent Application
No. 2,109,621 filed June 8, 1992.
A fastening system having a dense array of small prongs is preferred
because such a fastening system is generally capable of engaging the fibers of
the
nonwoven materials of the sanitary napkin or the fibers of the wearer's
undergarment and does not require a dedicated receiving surface. As used
herein,
the term "dedicated receiving surface" will refer to any element joined to the
1 o sanitary napkin 20 or the undergarment of the wearer, which element has
the
primary function of acting as the complementary receiving surface for the
oriented
hook fastening material 54. As used herein, the term "non-dedicated hook
fastening material" will refer to a hook fastening material which is capable
of
engaging the fibers of the nonwoven materials of the sanitary napkin (such as
15 topsheet materials) or the fibers of the wearer's undergarment (such as
woven
materials) and does not require a dedicated receiving surface. When a non-
dedicated hook fastening material 54 is said to be "capable" of engaging the
fibers
of the nonwoven materials of the sanitary napkin or the fibers of the wearer's
undergarment, this means that the materials of the sanitary napkin or
2 o undergarment may be used as a receiving surface for the non-dedicated hook
fastening material. However, the non-dedicated hook fastening material is
typically not limited to use with such receiving surfaces (e.g., materials of
the
sanitary napkin and materials of the wearer's undergarment) and dedicated
receiving surfaces may also be used.
2 5 A particularly "skin-friendly" mechanical fastening system and methods of
producing such a fastening system are disclosed in Canadian Patent Application
No. 2,148,946 filed December 8, 1993.
The hook fastening material 54 of Figure 4a may be formed on a substrate
24 discrete from the sanitary napkin 20 and then cut and applied to the
sanitary
3 o napkin 20. However, the hook fastening material shown in Figure 4a is
particularly preferred because the prongs 122 can be formed directly on the
~. .-.,~,;
24
backsheet 42 of the sanitary napkin as the sanitary napkin is being made, and
the
orientation of the hook fastening material can be controlled by azimuthally
angling the individual prongs 122 according to the methods of the above-
referenced patents and patent applications.
Another example of a suitable hook fastening material 54' which also can
be formed directly on the sanitary napkin, is shown in Figure 4b. The hook
fastening system 54' of Figure 4b comprises a prong 122 comprising a base
126',
shank 128' and a generally semispherically (mushroom) shaped engaging means
130'. The term "semispherical" means a generally round shape, protruding in
1 o multiple directions and is inclusive of hemispheres and spheres, but not
limited to
regular shapes. This geometry, particularly the generally spherically shaped
engaging means 130' structure, provides the advantage that less disturbance to
the
strands of the receiving surface typically occurs when the engaging means 30'
is
removed from the receiving surface. This causes less visible damage to the
15 receiving surface, allowing it to be reused a greater number of times.
One method for making the hook fastening system 54' of Figure 4b, is by
forming the prongs 122 of Figure 4a according to the methods of the above-
referenced patents and patent applications, and heating the engaging means 130
and distal end of the prong to at least the melting point. This is
accomplished by
2 o bringing the engaging means 130 and distal ends of the prongs 122 to a
heat
source longitudinally directed toward the plane of the substrate so that the
base
126' and the proximal end of the shank 128' are not heated to at least the
melting
point. A suitable method is to bring the highest elevation of the prong to
within
about 3.3 millimeters to about 10.1 millimeters (0.1 to 0.4 inches) of a heat
source,
2 5 such as a hot wire heated to about 440°C.
Methods of forming the prong 122' of Figure 4b are more fully described
in the aforementioned U.S. Patent 5,230,851 granted July 27, 1993; and U.S.
Patent 5,116,563 issued May 26, 1992 to Dennis A. Thomas and David J.K.
Goulait.
25
Additional examples of suitable oriented hook fastening materials 54, are
shown in Figures 4c and 4d. The hook fastening materials 54 shown in Figures
4c
and 4d, comprise engaging elements 55 that are integral with the base
materials
84. Methods of producing such fastening materials are disclosed in U.S. Patent
s 3,557,407, "Apparatus For Surface Forming Sheet Material", issued January
26,
1971.
2. Function of the Sanitar~pkin
WO 94/13239 215 I 4 8 ~ - PCT/US93/11910
26
The function of the sanitary napkin of the present invention
will now be described in greater detail with relation to the
wearer's undergarments.
The hook fastening material of the sanitary napkin 20
provides a secure attachment to an undergarment by creating shear
forces on the undergarment that are oriented on substantially
opposite directions. Figure 6 is a depiction of an undergarment
11 of the type commonly worn by many women and well known as a
panty: A panty 11 comprises a front section 10, a back section
12, and a crotch portion 14 which joins the front and back
sections. The front section 10 extends from the crotch portion
14 to the front waistband 15. The back section 12 extends from
the crotch portion 14 to the back waistband 17. The crotch
portion 14 comprises two side edges 16, 16' and center crotch
portion 18.
The sanitary napkin 20 of the present invention is utilized
by placing the sanitary napkin 20 in a panty 11 as shown in
Figure 6a. The center of main body portion 22 is placed in
crotch portion 14 of the panty with the first half 80 of the main
body portion 22 extending towards the front section 10 of the
panty 11 and the second half 82 of the main body portion 22
extending towards the back section 12 of the panty 11. The
oriented hook fastening materials 54 are placed in contact with
the inner surface of the crotch portion 14 of the panty 11 such
that the engagi ng el ements 55 of the fi rst hal f 80 mechani cal ly
engage the fibers of the front section 10 and the engaging
elements 55 of the second half 82 mechanically engage the fibers
of the back section 12.
As a result of the engaging elements 55 of the hook
fastening material 54 of the first half 80 mechanically engaging
the fibers of the front section 10 of panty 11, the first half 80
of the sanitary napkin 20 is restricted or substantially
prevented from moving toward the crotch portion 14 of the panty
11. However, the first half 80 of the sanitary napkin 20 is able
to move in a direction away from the crotch portion, i.e., toward
the front waistband 15 of the panty 11, without mechanically
engaging the fibers of the front section 10 of panty 11.
PCT/US93/11910
WO 94/13239 ~ ~~~' ' 27
Therefore, the first half 80 of the sanitary napkin 20 is able to
move toward the front waistband 15 of the panty 11 with relative
ease. Accordingly, any movement of the first half 80 of the
sanitary napkin 20 will tend to be movement away from the crotch
portion 14 of the panty 11, i.e., in the direction of the front
waistband 15 of the panty 11.
Likewise, as a result of the engaging elements 55 of the
hook fastening material 54 of the second half 82 mechanically
engaging the fibers of the back section 12 of panty 11, the
second half 82 of the sanitary napkin 20 is restricted or
substantially prevented from moving toward the crotch portion 14
of the panty 11. However, the second half 82 of the sanitary
napkin 20 is able to move toward the back waistband 17 of the
panty 11 without mechanically engaging the fibers of the back
section 12 of panty 11. Therefore, the second half 82 of the
sanitary napkin 20 is able to move toward the back waistband 17
of the panty 11 with relative ease. Accordingly, any movement of
the second half 82 of the sanitary napkin 20 will tend to be
movement away from the crotch portion 14 of the panty 11, i.e.,
in the direction of the back waistband 17 of the panty 11.
This arrangement of the hook fastening materials 54 creates
shear forces between the first half 80 of the sanitary napkin 20
and the front section 10 and between the second half 82 of the
sanitary napkin 20 and the back section 12. The shear forces of
the first half 80 and the second half 82 provide a secure
attachment of the sanitary napkin 20 to the panty 11 by having
the forces of the first half 80 and the second half 82 opposed to
each other.
An additional benefit obtained by this arrangement, is that
any movement of the sanitary napkin 20 relative to the panty 11
will tend to be movement of the first half 80 and movement of the
second half 82 toward the front waistband 15 and rear waistband,
respectively. Therefore, movement of the sanitary napkin
relative to the panty 11 tends to draw the sanitary napkin 20
closer to the body of the wearer. This is especially true in
embodiments having the transverse center 106 of the sanitary
napkin 20 substantially free of any securement member, i.e., hook
WO 94/13239 '~ PCTIUS93/11910
28
fastening material, pressure sensitive adhesive, and the like,
because the transverse center 106 of the sanitary napkin 20 is
then able to decouple from the panty central crotch portion 18
and move closer to the vaginal opening. Such embodiments are
shown in Figures 3 and 7 and discussed in greater detail
hereinbelow.
C. Alternate Embodiments of the Sanitarv Naokin of
the Present Invention
In an alternate sanitary napkin embodiment embodiment of the
present invention shown in Figure 2, the main body portion 22 is
further divided by the longitudinal centerline L into quarters,
86, 87, 88, and 89. Each quarter (86-89) of the main body
portion 22 comprises a pad securement member 67 comprising an
oriented hook fastening material 54. The hook fastening material
54 of each quarter (86-89) of the main body portion 22 comprises
engaging elements 55 oriented in a direction having a vector
component perpendicular to the principal transverse centerline T
and a vector component perpendicular to the longitudinal
centerline L. Such an arrangement results in the shear forces of
the hook fastening material 54 being oriented generally toward
the point where the longitudinal centerline L and the transverse
centerline T intersect.
In another alternate sanitary napkin embodiment of the
present invention shown in Figure 3, the hook fastening material
54 of each quarter (86-89) of the main body portion 22 comprises
engaging elements 55 oriented in a direction having a vector
component perpendicular to the principal transverse centerline T
and a vector component perpendicular to the longitudinal
centerline L. However, rather than the entire garment side of
each quarter (86-89) being covered with an oriented hook
fastening material (as in the embodiment of Figure 2), only a
portion of each quarter (86-89) comprises an oriented hook
fastening material. This arrangement leaves the transverse
center 106 and the longitudinal center 112 of the sanitary napkin
20 substantially free of any fastening material and will
closer to the body of the wea
PCT/US93/11910
WO 94/13239 ~ ~ ~ . 29
therefore allow the transverse center 106 and the longitudinal
center 112 of the sanitary napkin 20 to detach or decouple from
the undergarment and may improve the contact of the sanitary
napkin 20 with the vaginal opening.
As can be seen in Figures 3, 3a, and 3b, the transverse
center 106 of the sanitary napkin 20 is that portion of the main
body portion 22 which extends transversely from one longitudinal
side 22a to the other longitudinal side 22a and extends
longitudinally from about the first transverse end 102 to about
the other transverse end 104. The first transverse end 102 of
the main body portion 22 is that portion of the main body portion
22 which extends transversely from one longitudinal side 22a to
the other longitudinal side 22a and extends longitudinally from
one transverse side 22b to about the transverse center 106. The
second transverse end 104 of the main body portion 22 is that
portion of the main body portion 22 which extends transversely
from one longitudinal side 22a to the other longitudinal side 22a
and extends longitudinally from the other transverse side 22b to
about the transverse center 106.
As can be seen in Figures 3, 3a, and 3b, the longitudinal
center 112 of the main body portion 22 is that portion of the
main body portion 22 which extends longitudinally from one
transverse side 22b to the other transverse side 22b and extends
transversely from about the first longitudinal end 108 to about
the second longitudinal end 110. The first longitudinal end 108
' of the main body portion 22 is that portion of the main body
portion 22 which extends longitudinally from one transverse side
22b to the other transverse side 22b and extends transversely
from one longitudinal side 22a to about the longitudinal center
112. The second longitudinal end 110 of the main body portion 22
is that portion of the main body portion 22 which extends
longitudinally from one transverse side 22b to the other
transverse side 22b and extends transversely from the other
longitudinal side 22a to about the longitudinal center 112.
Another alternate sanitary napkin embodiment of the present
invention is shown in Figure 3a. The sanitary napkin of Figure
3a is substantially the same as that shown in Figure 3. However,
WO 94113239 PCT/US93I11910
the pad securement member 67 of the sanitary napkin 20 of Figure
3a comprises two additional patches of an oriented hook fastening
material 54. One patch of oriented hook fastening material 54 is
positioned at about the transverse center 106 on one side of the
principle longitudinal centerline L and is oriented in a
direction having a vector component perpendicular to the
longitudinal centerline L. The other patch of oriented hook
fastening material 54 is positioned at about the transverse
center 106 on the other side of the principle longitudinal
centerline L and is also oriented in a direction having a vector
component perpendicular to the longitudinal centerline L.
Another alternate sanitary napkin embodiment of the present
invention is shown in Figure 3b. The sanitary napkin of Figure
3b is substantially the same as that shown in Figure 3a.
However, the pad securement member 67 of the sani tary napki n of
Figure 3b comprises two additional patches of an oriented hook
fastening material 54. One patch of oriented hook fastening
material 54 is positioned at about the longitudinal center 112 on
one side of the principle transverse centerline T and is oriented
in a direction having a vector component perpendicular to the
transverse centerline T. The 'other patch of oriented hook
fastening material 54 is positioned at about the longitudinal
center 112 on the other side of the principle transverse
centerline T and is also oriented in a direction having a vector
component perpendicular to the principle transverse centerline T.
' Another alternate sanitary napkin embodiment of the present
invention having a transverse center 106 that may detached or
decoupled from the undergarment, is shown in Figure 7. The
sanitary napkin 20 of Figure 7 comprises a pad securement member
67 comprising an oriented hook fastening material 54 positioned
at about the first transverse end 102 and another oriented hook
fastening material 54 positioned at about the second transverse
end 104. Each of the hook fastening materials 54 are oriented in
a direction having a vector component perpendicular to the
transverse centerline T, and the transverse center 106 is
substantially free from any type of fastening member.
WO 94/13239 , PCT/US93/11910
Another alternate sanitary napkin embodiment of the present
invention is shown in Figure 7a. The sanitary napkin embodiment
of Figure 7a is substantially the same as that shown in Figure 7,
however, the pad securement member 67 of the sanitary napkin ZO
of Figure 7a additionally comprises a pressure sensitive adhesive
66 positioned in the transverse center 106 of the main body
portion 22. The pressure sensitive adhesive 66 would secure the
transverse center 106 of the sanitary napkin to the crotch of the
panty. Even if the pressure sensitive adhesive 66 shifts during
application of the wearer's pants, the oriented hook fastening
material 54 would tend to maintain proper positioning of the main
body portion 22 in the panty and prevent "bunching" of the main
body portion 22.
Another alternative sanitary napkin embodiment is shown in
Figure 7b. The sanitary napkin embodiment of Figure 7b is
substantially the same as that shown in Figure 7, however, the
pad securement member 67 of the sanitary napkin of Figure 7b
comprises two additional patches of an oriented hook fastening
material 54. One patch of oriented hook fastening material 54 is
positioned at about the transverse center 106 of the sanitary
napkin 20 on one side of the principle longitudinal centerline L
and is oriented in a direction having a vector component
perpendicular to the longitudinal centerline L. The other patch
of oriented hook fastening material 54 is positioned at about the
transverse center 106 of the sanitary napkin 20 on the other side
of the principle longitudinal centerline L and is also oriented
in a direction having a vector component perpendicular to the
longitudinal centerline L.
An embodiment wherein essentially the entire perimeter of
the main body portion comprises a hook fastening material which
is oriented in a direction having a vector component
perpendicular to the transverse centerline or perpendicular to
the longitudinal centerline, is also contemplated. As used
herein, the term "perimeter of the main body portion" shall refer
to that portion of the main body portion 22 which is
substantially adjacent the longitudinal edges 22a and the
transverse edges 22b of the main body portion 22. In such an
32
embodiment a portion of the transverse center 106 and a portion of the
longitudinal center 112 of the main body portion 22 will be substantially free
of
any fastening material and will therefore allow that portion of the main body
portion 22 to detach or decouple from the undergarment and may improve the
s contact of the sanitary napkin 20 with the vaginal opening. Alternatively,
that
portion of the main body portion 22 which is substantially free of any
oriented
hook fastening material may be provided with an adhesive fastener.
In another alternate embodiment of the present invention, such as that
shown in Figure 5, the sanitary napkin may also comprise wings, or flaps.
1 o Generally, flaps extend laterally from the main body portion 22 and are
intended
to be folded around the edges 16, 16' of the wearer's panty 11 in the crotch
region
14. Thus, the flaps are disposed between the edges of the wearer's panties in
the
crotch region and the wearer's thighs.
The general construction of flaps 24 suitable for use in the present
15 invention (without the oriented hook fastening material 54 of the present
invention) is described in greater detail in patents, such as U.S. Patent
4,917,697
issued to Osborn; Canadian Patent Application No. 2,079,537-9 filed September
30, 1992; and Canadian Patent Application No. 2,079,557-3 filed September 30,
1992.
2 o The overall size of the flaps 24 can be readily selected by those skilled
in
the art. Preferably, the flaps 24 are sized so that the sanitary napkin 20 is
from
about 10 to about 23 centimeters wide between the distal edges 34 of the flaps
at
their greatest separation. Preferably each flap 24 is from about 5 to at least
about
19 centimeters long in the direction parallel to the principal longitudinal
centerline
2 s L of the sanitary napkin. However, the flaps 24 may be as small as 0.5
centimeters long in the direction parallel to the principle longitudinal
centerline L.
~-'..~,,:
2 I ~ I 4 8 5 PCT/US93/11910
WO 94/13239
The shape of the fl aps 24 can be sel ected by those ski 11 ed
in the art. Preferably, not only are the flaps 24 mirror images
of each other, the two halves of each flap 26 and 28 are also
symmetrical about the flap transverse centerline T1. (It should
be understood that the shape and orientation of the flaps
described herein are those of a preferred embodiment. They are
not mandatory design features.)
Preferably, as in the sanitary napkin 20 illustrated in
Figure 5, the flaps 24 are positioned slightly forward of the
principal transverse centerline T of the sanitary napkin. (In
such a case, the flap transverse centerline T1 does not coincide
with the principal transverse centerline T of the sanitary napkin
20.) The flaps 24, however, are preferably evenly spaced from
the principal longitudinal centerline L of the sanitary napkin.
In a preferred embodiment, the flaps 24 are joined with the
main body portion 22 along lines of juncture 30. The lines of
juncture can be concave, straight, (or, but preferably not,
convex) relative to the principal longitudinal centerline L. The
lines of juncture 30 may comprise those lines or areas where
separate flap elements are joined to the main body portion 24.
Alternatively, when the flaps 24 are integral with the main body
portion 22, the lines of juncture 30 may represent lines of
demarcation between the main body portion 22 and the flaps 24
(although it is not necessary that there be a precise line of
demarcation).
The flaps 24 can be joined with the main body portion 22 in
a number of different manners. Many of the different ways a
component (such as the flaps 24) can be "joined to" or
"associated with", etc. another component, are set forth in .the
definitions of these terms contained in U.S. Patent 5,007,906
entitled "Decoupled Sanitary Napkin" which issued to Osborn, et
al. on April 16, 1991. When the flaps comprise separate
elements, they can be joined to the main body portion 22 by any
techniques known to those skilled in the art. Such techniques
include, but are not limited to adhesives, heat and/or pressure,
ultrasonics, etc.
34
It is not necessary that the flaps 24 extend from (or be joined along) the
longitudinal edges 22a of the main body portion 22. The flaps 24 can join
inward
(or "inboard") from the longitudinal edges 22a toward the longitudinal
centerline
L such as is shown in U.S. Patent 4,900,320 issued to McCoy on February 13,
s 1990. The flaps 24 can, thus, each be joined to the main body portion 22
along
the principal longitudinal centerline L, or along the longitudinal edges 22a
of the
main body portion 22, or at any place between the principal longitudinal
centerline
L and the longitudinal edges 22a of the main body portion 22. The flaps 24
will,
of course, generally be on opposite sides of the principal longitudinal
centerline L.
i o Referring to Figure 5, the outer surface of the flap 24, adjacent the
distal
edge 34 of the flap, preferably comprises a flap securement member such as a
pressure sensitive adhesive, a mechanical fastener, or the like. The flap
securement member 56 is used to assist in maintaining the flap 24 in position
after
it is wrapped around the edge of the crotch portion of the panty as described
15 below. The flaps 24 can be maintained in position by attaching the flaps 24
to the
undergarment, or to the opposing flap. Suitable adhesive fasteners are
described
in greater detail in U.S. Patent 4,917,697.
If the flap securement member 56 comprises an adhesive, the adhesive is
preferably protected by a release material to protect the adhesive from dirt,
to
2 o prevent the adhesive from drying out, and keep the adhesive from sticking
to
extraneous surfaces prior to use. Suitable release liners are described in
U.S.
Patent 4,917,697. The sanitary napkin 20 may comprise a unitary release member
which is joined to the sanitary napkin and eliminates the need for separate
pieces
of release material. Unitary release members are discussed in greater detail
in
2 s Canadian Patent Application No. 2,13 8,246 filed June 14, 1993.
The flap securement member 56 is not limited to adhesive attachment
means. Any type of fastener used in the' art can be used for such purpose. For
example, the flap 24 of sanitary
1
2l ~.1
WO 94113239 ~ PCTIUS93I11910
napkin 20, could be secured to the wearer's undergarment by the
fastener described in U.S. Patent 4,946,527 entitled
"Pressure-Sensitive Adhesive Fastener and Method of Making the
Same" issued to Battrell on August 7, 1990. However, embodiments
wherein the flap securement member comprises both a hook
fastening material and an adhesive are also contemplated.
The flap securement members 56 of the sanitary napkin 20
preferably comprise an oriented hook fastening material 54 such
as the hook fastening materials described herein. In a
preferred embodiment the flap securement member 56 will comprise
an oriented hook fastening material which is oriented in a
direction perpendicular to the principle longitudinal centerline
L. Such flaps 24 can be used on any of the sanitary napkin
embodiments described herein. Additionally, flaps 24 with the
oriented hook fastening material 54 may also be used on sanitary
napkins having a pad securement member 67 which is comprised of a
pressure sensitive adhesive.
Thus, the present invention provides a sanitary napkin
having an oriented hook fastening material which improves body
contact with the sanitary napkin and, thereby, improves the
effectiveness of the sanitary napkin.
While particular embodiments of the present invention have
been illustrated and described, it would be obvious to those
skilled in the art that various other changes and modifications
can be made without departing from the spirit and scope of the
invention. It is therefore intended to cover in the appended
claims all such changes and modifications within the scope of
this invention.
